A vibration box on a negative pressure cup capable of strengthening airtightness for achieving waterproof, anti-collision and noise reduction functions, comprising a vibration box installed on a negative pressure cup； a vibration motor disposed inside the vibration box； a vibration box back cover disposed on a back of the vibration box for sealing； a waterproof rubber element disposed on the vibration box back cover and a contact surface of the vibration box, the vibration box back cover and the contact surface of the vibration box being reciprocally disposed with flanges and grooves, a surface of the waterproof rubber element being disposed with recesses with a concave cross section, each of the recesses being sleeved to one of the flanges and embedded in the groove to be sealed； a noise reduction cover hooded outside the vibration motor； and a buffer cushion disposed between the vibration motor and the noise reduction cover.
